Labyrinth packing



Jan. 1, 1935.

o. A. WIBE'RG LABYRINTH momma Filed Jan. 18, 1955 1 2 Sheets-Sheet 1 Jan. 1, 1935. O MBERG 1,986,087

LABYRINTH PACKING Filed Jan. 18, 1933 2 Sheets-Sheet 2 Patented Jan. 1', 1935 UNlTE D f S-TATE LABYBINTH PACKING Oscar AntonfWiberg, Finsponfg, Sweden.

Application January 18, 1933, Serial No. 652,383 In Germany January 21 1932 12 Claims. 1(o1. 253-465) gaging the spaces between the projections of the other disk. The invention has more particularlyreference to packings of this type which areiadapted for usein connection. with turbines or other machinesin which one packing disk is carried by a rotary wheel or a similar element, whilethe other disk is carried by a stationary part. I

The object of the invention is to provide a labyrinth packing ofthe above said type by which. within a given diameter a high sealing efiect may be obtained as compared with that of labyrinth .packings of hitherto known designs. With this and other objects in view, the packing according to the invention comprises two or more pairs of disks or disk sections whichare dis-' placed insuch a way with relatio'n to each other that the'variou's pairs. of disks or disk sections are, at least in part, in overlapping relation to eachother. q In the accompanying drawings, two embodivmerits of labyrinth packings according to. this invention are illustrated. Fig. 1 isa cross section of one half of a labyrinth packing according to one embodiment as used in connection with a radial flow steam turbine, part of which is shown in axial section. Fig. 2 is a similarcview-of a packing according to the other embodiment'likewise as used in connection with a radial flow steam turbine. V

In both of the embodiments shown in the drawings, the labyrinth packingis positioned between a rotary turbine wheel and the steam chest.

With reference to Fig. 1, the numeral 1 indicatesone shaft of a radial flow steam turbine having two blade disks rotating in opposite directions. 2 is the blade disk carried by the shaft 1. The other shaft as well as the blade disk carried thereby are not shown in the drawings, as this is unnecessary for the understanding of the invention. The turbine disk 2 carries an additional disk section 2' by means of radial bolts 3. The turbine disk sections 2 and 2 carry the blading 4. 5 represents a steam chamber to which high pressure steam is supplied through V pipe 6 and from which said steam is passed to the innermost, blade ring of theblading 4. The'stearn chamber 5 together with. a "surrounding steam chamber '1 are both contained in the steam chest '8. The chamber 7 is in communication and, an additional steam chest 8; The by n h turbine disk 2 by means of axially-extending bolts with an inner stage of the blading 4 to allow 1 the admitting of overloadingsteam to the bladlng or the withdrawal of bleeding steam therefrom.. The steam chest 8:is bounded on its side facing the turbine disk 2 by a labyrinthpacking comprising. two sections 9 and-10. Each of these sections comprises two disks; oneoi which, 11 or "12 respectively, is connectedto the turbine disk 2 and rotates. therewith, whereasthe other disk, 13 or 1i respectively, of each section isconnctd to the steam chest 8. The packing section'l0 is displaced axially with relation to the sectionP9 nearer to the bladingfi than the section 9fis. The inner diameterof section 10 is less than the outer diameter1of section9 so that'the twopackso that, in the embodiment shown, it is situated ing sections are in overlapping" relation to each other almost to the entire radial extent of section 10; The space between the sections 9 and IO afiords .a connecting passage 15 between a stage of comparatively low pressure of the-bladingi chamber 16 in the steam packing disk 11 isattached to the 17. Said bolts are inserted frorn'the inner side of turbine disk 2 which will render the attach- .ment Qty-the disk .11 very simple as compared with the methods hitherto used inthe mounting of labyrinth packings, according-to which the bolts are inserted from the outer side of the labyrinth disk. The labyrinth disk 12 iscarried by the turbine disk 2 by means of axial pins 18. For sealin'g purposes a 'packing ring19 is inserted between the disks' 2fand'1-2, In order to W c amplthe labyrinthdisk 12 to the turbine 2 with suffficient power, a cylindrical ring 21 is inserted between the labyrinth disk 11 and" a part 20 of the labyrinth disk 12 closely. iittingin a shoulder formed in the labyrinth turbine disk 2, so'that the ring 21 maybe pressed against known means to the-cylindrical partitions of the" steam chest 8. The labyrinth disk 14 is pivotally connected to the stationary disk 23 of an additionallabyrinthipacking.24 by means of aflexible:

connecting. member 22' affording a steam tight joint between the disks 14 and 23. Said disks 14* and 2 3are carried by the outer circumferential wall 27 of the steam chest 8- through the intermedium of an expansion ring 25 and a set of radialfbolts 26. Said expansion ring 25 is-ins'e rta through which the steam chambers49, 50 communicate with the respective inner stages of the the wheel 41 as well. 45. and 46 are connected to each otherby a set of radial bolts 47. Steam may be admitted to ed between the members 23 and 27, whereas the bolts 26 are mounted to hold a collecting chamber 28 in place with relation to the wall 27. Said collecting chamber communicates with the space 29 between the packing sections 10 and 24 and.

The labyrinth packing above described is ca pable of affording an effective reduction of the leakage of steam from the high pressure chamber 5 to the atmosphere within a restricted diameter.

In Fig. 2 there is shown a modified. embodiment of the invention which is still more effective than that above described.

With reference to Fig. 2, the numeral 40 designates the radial flow blading of a turbine having inaddition tothe radialflow main blading 40 an axial flow blading comprising two rotary wheels 41 and 42 and the associated sets of guide blades 43 and 44, respectively. The radial flow blading 40' is carried, substantially, by a turbine disk comprising two sections 45 and 46 and, as far as the outermost blade rings are concerned, by The turbine disk sections the blading 40 from three separate. steam chambers 48, 49 and 50 concentrically surrounding each other in the order stated. Said three steam chambers are all contained in one and the same the blading 40, from chamber 49 steam of high pressure may be admitted 'for overloading purposes to an inner stage of the blading and from chamber50 steam of high pressure may be ad mitted for the same purpose to a stage of the bladingg40 situated at a still greater distance from the axis of the turbine. .The chambers. 49 and 50' may also be used for bleeding purpose. Provided between the rotary turbine disk 45, 46 and the steam chest containing the chambers 48, 49, 50, is, aradially extending labyrinth packing 51. 1 Said packing comprises a disk 52 carried by the rotary turbine disk 45, 46 and another disk 53 carried by the stationary cylindrical partitions 54,55 and outer wall 56 of the steam chest.

.The two packing disks 52, 53 as well as the turbine disks 45, 46 are formed with passages 57, 58

blading 40. Situated outside the passage 58 is not bnly the outermost section of the labyrinth packing 51 but also aseparate labyrinth packing 59 which is located substantially between the same inner andouterdiameters as the said outermost section is. The labyrinth packing 59 comprises a rotarydisk 60 attached to the turbine disk section 46 and a stationary disk 61 attached to stationary parts of the turbine in a way to be hereinafter described. Provided outside the packing 59 so as to communicate with the outer through radial borings 63, and has at its other end a steam bleeding hole 631 and. a packi g 6 prevent leakage of steam from chamber 62 to the interior of the turbine casing.

The stationary disk 61 of packing 59 carries at its outer periphery a substantially cylindrical wall 65 pivotally connected to a, likewise, cylindrical wall 66 projecting from the stationary disk 67 of the packing 64 by means of a connecting member 68. Said connecting member is adapted to aiford a steam tight joint between the walls 65 and 66, and is provided with a cylindrical extension 69 engaging an annular groove formed in the outer wall 56 of the steam chest. The members 65, 66 and 69 may, preferably, be flexible in order that they may be capable of taking care of the variations of the dimensions of the packing disks 61 and 67 due to variations of the temperature. The members 65, 68 and 66 form together with the packing 59 the inner wall of chamber 62, whereas the outer circumferential wall of this chamber is representedv by a separate cylindrical member 70 inserted between the rotary disk 71 of the packing 64 and the turbine disk section 46. Inside the extension 65 there is provided a space 72 in communication with the outer 'end of the packing 51, in which the steam leaking through said packing'will be received and from which said steam may pass to the inner end of the packing 59. In the steam channel between space 72 and the inner end of packing 59,as afforded by the space between the rotary disk 52 of packing 51 and the stationary disk 61 of packing 59, labyrinth packing elements are provided, as shown at 73, thereby aifording an additional packing to prevent leakage of the steam that has passed the packing 51 and has collected in the space 72. By this feature, a corresponding reduction of the leakage losseswill be obtained. The rotary disk 60 of packing 59 carries at its inner circumference a cylindrical extension 74 engaging a groove formed in the disk 52 so as to aiTord a steam tight joint at that point. Said extension 74 forms, as a result, an outer wall of the steam passage 58 where it passes inside the packings 59 and. 73

1. In a radial flow turbine, a rotary wheel with its blading, a stationary steam chest having a plurality of concentric chambers, and a labyrinth packing inserted between said wheel and said steam chest, said packing comprising a plurality of annular coaxial sections in radial overlapping relation to each other, each section including a rotary disk carried by the turbine wheel, a stationary disk carried by the steam chest'and a set of concentric sleeve shaped elements alternately carried by one and the other of said disks, one of said sections being located between an outer wall of the steam chest and the turbine wheel, means to carry this section between the inner section of the packing, and the turbine wheel, said carrying means surrounding the inner section and being spaced therefrom by a connecting passage between an inner stage of the turbine blading and a chamber of the steam chest.

2. In a radial flow turbine, a rotary wheel having blading, a steam chest, a set of axially displaced labyrinth packings in series inserted between said wheel and said steam chest, an additional labyrinth packing both axially and radially displaced with relation to said first-mentioned 1*,986j087 packings; each 'of saidjpa inss comprisin ia' tationary: annular disk arotaryannular 'disk, a substantially cylindrical extension on the-stationary-disk of? the labyrinth packing-nearest the rotary turbine wheel; a similar extensionon the stationary disk: of", said additional packing,- and a connecting element pivotally connecting said a two extensions while affording a'steam-tightjoint therebetween. so as to allow. the said extentions .to formatight wall:

' 3: m .a radial flowturbine, a tearywheel having blading; a steam chest, a set ofaxially displaced labyrinth packings: m seriesinserted betweensaid wheel" and, said steam chest, an additional labyrinthpacking both axially and radially with the free ends of said extensions, and a substantially cylindrical flexible member formed in tegrally with said ring and engaging saidsteam chest and carried thereby.

4. In a radial flow turbine, a rotary turbine Wheel, a stationary part to the side of said wheel, a

'main labyrinth packing comprising a disk attached to said .wheel, another disk attached to said stationary part, and concentric sleeve shaped elements alternately carried by said disks, and an additional labyrinth packing of less radial length than said main packingalso inserted between said wheel and said part, said additional packing being displaced axially withrelation to the main packing so as to overlap same radially at the outer periphery thereof, while having substantially the same outer diameter as the main packing.

5'. In a radial flow turbine, a rotary turbine wheel, a stationary part to the side of said wheel, a main labyrinth packing inserted between said wheel and said part, an additional labyrinth packing of less radial length than-said main packing also inserted between said wheel and said part, said additional packing being displaced axially with relation to the main packing so as to overlap same radially at the outer periphery thereof,

a connecting passage between said packings to connect them in series with each other, and concentric sleeve shaped elements arranged in said passage so as to form a labyrinth path therein.

6. ,In a radial flow turbine, a rotary wheel, a stationary part to the side of said wheel, a main labyrinth packing and an additional labyrinth packing of less radial length than the main packing inserted between said wheel and said part with the additional packing displaced axially with relation to said main packing so as to radially overlap same at the outer portion thereof, each of said packings comprising a stationary disk, a rotary disk and concentric sleeve shaped elements alternately carried by one and the other of said disks, adjacent disks of the packings having such sleeve shapedelements on both of their sides.

'7. In a radial flow turbine, a rotary wheel; a stationary steam chest tothe side of said wheel,

a main labyrinth packing situated between said.

-. to varying heating.

1 wheel and inner; partsof said steam ch'est, "and an additional labyrintnpacking situatedbetwe'en taid'wheel and-an outei wall cf said steamchest,

said additional packing being displaced axially w thmelation to-thqmain packing so as to overlap 'sameradially at'theouter-periphery thereof, the

connection between-the additional packing and I said outer wall including a" sleeve-shaped member 4 surroundingthe-main packing.

'8; In a 'radiabflow turbine,- a'rot ary wheel, a stationary steam chesttojthe sideofsaidwheel,

a rrnain' labyrinth packing comprising a rotary diskrattachedto-theturbine wheeland a stationarydiski attached to: inner parts of thesteam chest, an additional labyrinth pack-ing 'in' series with the-j main packing comprising. a; rotary disk carried 'bythe turbinewheel 'anda stationary disk attached to an outer wall of thefsteain chest, additional" packing being 'displaced axially with relation to the main packing so as to overlap same radially at the outer portion thereof, and a ring clamped between the rotary disk of the main packing and the rotary disk of theadditional packing to maintain the latter in engagement with the rotary turbine wheel.

9. In a radial flow turbine, a rotary wheel, a stationary steam chest to the side of said wheel,

a main labyrinth packing between said wheel and said steam chest comprising a rotary disk attached to said wheel and a stationary disk attached to inner parts of the steam chest, a. first additional labyrinth packing in'series with said mainpacking displaced axially with relation thereto'so as to overlap same radially at the outer portion thereof, a second additional labyrinth packing in series with the first additional packing, said second additional packing being displaced axially and radially with relation to the first additional packing, the additional packings comprising each a 'rotary'disk connected to the rotary wheel of the turbine and a stationary connecting means beingprovided between said stationary disks and said outer wall to take care of expansion and contraction of said disksdue 10. In a radial flow turbine, a rotary wheel,

a stationary steam chest tothe side of said wheel,

a main labyrinth packing comprising' arotary disk carried by said wheel and a stationary disk carried byinner parts of the steam chest, a first additional labyrinth packing in series with the main packing comprising a rotary disk carried by the turbine wheel and a stationary disk carriedby an outer wall of the steam chest, said first additional packing being displaced axially with relation to the main packing so as to radially overlap same at the outer portion thereof, a sec-' nect said collecting chamber to said outer wall so as to allow it to expand radially with relation thereto.

11. In a radial flow turbine, a rotary wheel, a stationary steam chest to the side of said wheel,

'a main labyrinth packing between said wheel and said steam chest comprising a rotary disk carried by said wheel and a stationary disk carried by inner parts of the steam chest, an additional packing in series with the main packing comprising a rotary disk carried by the turbine wheel and a stationary disk carried by an outer wall of the steam chest, said additional packing being axially displaced with relation to the main packing as to overlap same radially at. the outer portion thereof, a substantially axial steam passage formed through the main packing at a smaller diameter than the innerdiameter of the additional packing so as to be surrounded thereby, and a projection on the rotary disk of the additional packing to forma tight sealing between said passage and said surrounding additional packing.

12. In a radial flow turbine, a rotary wheel, a

,stationary steam chest to the side of said wheel,

a main labyrinth packing between said wheel and said steam chest comprising a rotary disk carried by said wheel and a stationary disk carried by inner parts of the steam chest, an additional 7 packing in series with the main packing com-' prising a rotary disk carried by the turbine wheel and a stationary disk carried by an outer wall of the steam chest, said additional packing being so displaced with relation to the main pack- OSCAR ANTON WIBERG. 

